The present invention relates to a method of supplying empty tubes to winding devices of a textile machine, such a textile machine comprising a plurality of operating units arranged next to each other in at least one line and each equipped with a winding device as a part of the operating unit. At one end of the machine there is provided a tube container coupled with a tube conveyer arranged along the line of the operating units of the textile machine along which is also provided an attending unit adapted to travel along the line of the operating units. The attending unit contains handling means for moving a tube from the tube conveyer to a winding device, the handling means of the attending device laying into the winding device an empty winding tube prior to an attempt at rewinding. The invention also relates to a device for carrying out the method on a textile machine. The invention also relates to a device for stopping a tube on the conveyor for carrying out said method on a textile machine.
In automatic textile machines in which yarn or thread being produced is wound on a bobbin at each operating unit of the machine, the bobbin, when (fully) wound, must be removed from the operating unit and replaced by an empty tube. This replacement of a (fully) wound bobbin by an empty tube can be made manually or by means of an automatic attending device that, however, must be equipped with an empty tube ready to be inserted at the moment of said replacement.
There are known a number of methods for conveying tubes to the operating units of a textile machine. In one of them, the attending device carries a number of tubes along with it. Its drawback consists in the necessity to replenish the inevitably limited total number of tubes in the attending device thus cutting down the productivity of the attending device. Besides, the tubes, can fall out of the container of the attending device while the latter is moving from an operating unit to a next one.
Also known are systems of tube conveying in which one tube, currently replenished, is seated at each operating unit. The conveying proper is provided for, for instance, by means of chain or through conveyers. The chief drawback consists in the complicated state of the conveying and depositing means, which contain a large number of repeating components having high trouble incidence.
The drawbacks of the above tube conveying systems have been eliminated by a device disclosed in the patent U.S. Pat. No. 4,865,260 for distributing and delivering separate tubes, one at a time, to the winding units of a textile machine. The tubes are seated in the container separately on a moving device, and more specifically, on a conveyer equipped with pins on which the tubes are seated without being in mutual contact. From the container, the tubes are doffed with a doffing device and transferred on the conveyer by which they are in their axial position, one at a time, transferred to gripping means adapted to stop the tube on the conveyer and to take it from the conveyer.
The device for conveying tubes disclosed in the CS AO 261 150 improved against the preceding device by positioning the tube stopped by means of the device on the conveyer to the position in which the projection of the tube axis to the active element of the conveyer is parallel with the direction of motion of this element. However, this modification complicates the device and does not eliminate the risk for the conical tube to fall out due to the oscillations of its narrow flange between the stationary passive members of the conveyer.
In operation, in such device the attending device fist stops at the winding unit where the full bobbin has to be replaced by a tube, and asks for a tube from the container. A tube is then released from the container and fed by the conveyer to the attending device that grips it with its receiving member and hands it over to its inserting member that puts it into bobbin arms of the winding device. Thereupon, yarn of thread is fixed to the tube, and the winding process is resumed.
If the resumption of the winding process has been unsuccessful, the empty tube remains gripped between the bobbin arms, and the attending device qualifies the operating unit in question as unattendable and moves to a next operating unit in need of attendance. The operating unit qualified as unattendable must be taken care of by an operator whose task is not only to remove the fault that has rendered impossible the rewinding, but also to take the tube out of the bobbin arms of the winding device and take it away.
Similar disadvantages has also the device for supplying empty tubes to the attending device disclosed in CS AO 261 150, in which the attending cycle is shortened, as compared with the previous method, in that in the handling arms of the attending device there is seated one tube so that there is no need for the attending device to wait until it receives a tube asked for by the attending device from the container but it can immediately proceed to attend the winding device of the operating unit in question. After the tube has been handed over between the bobbin arms of the winding device, the handling arms of the attending device grip the empty tube supplied in the meantime from the container by the conveyer and stopped by the stop mechanism of the attending device on the conveyer. The handling arms of the attending device assume an intermediate transport position, and the attending device is ready to attend another operating unit.
In this method as well, in case of an unsuccessful attempt at rewinding, the tube remains seated between the bobbin arms of the winding device and it is up to the operator to remove it. Since for instance spinning or winding machines contain a large number of operating units, and one operator has to take care of several machines, the carrying over of a considerable number of empty tubes is not only time-consuming but also potentially dangerous because the tubes, while being carried over, can fall on the machine or into the attending device and produce a failure in them.